Essential reading
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Essential reading
This is a must read thread.
http://www.pprune.org/rumours-news/3...-new-post.html
Said it to Orville, said it to Wibur and I'll tell you same thing.
http://www.pprune.org/rumours-news/3...-new-post.html
Said it to Orville, said it to Wibur and I'll tell you same thing.
Kharon that is frightening!
You've got to ask "What was he thinking that man??"
The scary thing is I know of Checkies in Oz who do similar displays of bad airmanship! It is almost like they are 'fatalistic' or they have no concept of basic aerodynamics....anyway good catch and I agree a MUST READ!
The report is now ready and can be downloaded here: 2011/40 | sht
(Click on "Last ned rapport"). It's in Norwegian but contains illustrations concerning the deep stall.
(Click on "Last ned rapport"). It's in Norwegian but contains illustrations concerning the deep stall.
ENGLISH SUMMARY
The flight was a skill-test for a candidate that was hired as a first officer on SA226-T(B) Merlins for
the operator Helitrans. He was one of two candidates that were employed by the company in early
2008. They underwent ground school and flight training in co-operation with the Swedish Type
Rating Training Organisation (TRTO) Trafikkhögskolan. Later it became clear that the Swedish
Civil Aviation Authority (CAA) did not accept skill-tests limited to first officer duties on a single
pilot certified airplane, as the Norwegian CAA did. The candidates did not possess the skills to act
as commanders on the Merlin, and there was a period of uncertainty while the operator and the
Norwegian CAA discussed how to conduct the skill-tests, in particular whether to use a simulator or
an actual airplane. After several months the issues were resolved and an examiner was appointed.
There was a limited slot on a Thursday and a Friday where the examiner, the instructor/commander
and the aircraft was available at Bergen Airport Flesland.
The first candidate performed the skill-test on Thursday. The weather was not suited for flying skilltests.
It was low ceiling, rain showers and winds up to 40 kt and turbulence. Turbulence caused the
stick pusher to activate during the demonstration of slow flight. The commander decided to pull the
circuit breaker for the Stall Avoidance and Stability Augmentation System (SAS²) presumably to
avoid nuisance activations of the stick pusher. After the slow flight demonstration, the examiner
asked the candidate to demonstrate a stall. The candidate found this exercise frightening as she
experienced great difficulties, having to use all her available physical strength to regain normal
flight with the engines on full power and in IMC conditions.
The weather was similar on Friday with even stronger winds. The SAS² circuit breaker was not
reset. This was confirmed during the start-up check. The examiner requested a similar program
during this skill-test as he did the day before. However, when it came to demonstrating stalls, the
examiner asked for a slow flight up to first indication of stall, and not an actual stall. He asked for
call outs and a minimum loss of altitude recovery. The commander undertook the tasks of adding
power and retracting gear and flaps on the candidate’s request. It was IMC. During this exercise the
crew lost control of attitude and airspeed. The stall warning came on, but the airspeed decreased,
even with full power applied. Radar data show that the altitude increased 200 – 400 ft during the
period where control was lost. Airspeed decreased to about 30 kt and a sink rate of about 10 000
ft/min eventually developed. The airplane hit the sea in a near horizontal attitude about 37 sec. after
control was lost. All three on board were fatally injured.
The accident aircraft was used for coastguard duties and was modified with external sensors and
antennas. The AIBN made a Computational Fluid Dynamics analysis in order to determine whether
these installations influenced on stability and flight characteristics in the slow flight and pre-stall
regime. It was found that the modifications reduced the overall performance, but did not result in
any significant degradation of stability and control in this regime. There was no investigation as to
any influence on the characteristics of a fully developed stall.
The AIBN is of the opinion that this accident highlights the need for a change in the current training
on initial stall recovery techniques, especially the focus on minimum loss of altitude at the expense
of breaking the stall by lowering the nose and thus reducing the angle of attack.
The AIBN has issued two safety recommendations to the Norwegian CAA; one regarding the
conduct of skill-tests for pilots in a multi crew concept on single pilot airplanes, and one suggesting
increased focus on flight examiners tasks.
The flight was a skill-test for a candidate that was hired as a first officer on SA226-T(B) Merlins for
the operator Helitrans. He was one of two candidates that were employed by the company in early
2008. They underwent ground school and flight training in co-operation with the Swedish Type
Rating Training Organisation (TRTO) Trafikkhögskolan. Later it became clear that the Swedish
Civil Aviation Authority (CAA) did not accept skill-tests limited to first officer duties on a single
pilot certified airplane, as the Norwegian CAA did. The candidates did not possess the skills to act
as commanders on the Merlin, and there was a period of uncertainty while the operator and the
Norwegian CAA discussed how to conduct the skill-tests, in particular whether to use a simulator or
an actual airplane. After several months the issues were resolved and an examiner was appointed.
There was a limited slot on a Thursday and a Friday where the examiner, the instructor/commander
and the aircraft was available at Bergen Airport Flesland.
The first candidate performed the skill-test on Thursday. The weather was not suited for flying skilltests.
It was low ceiling, rain showers and winds up to 40 kt and turbulence. Turbulence caused the
stick pusher to activate during the demonstration of slow flight. The commander decided to pull the
circuit breaker for the Stall Avoidance and Stability Augmentation System (SAS²) presumably to
avoid nuisance activations of the stick pusher. After the slow flight demonstration, the examiner
asked the candidate to demonstrate a stall. The candidate found this exercise frightening as she
experienced great difficulties, having to use all her available physical strength to regain normal
flight with the engines on full power and in IMC conditions.
The weather was similar on Friday with even stronger winds. The SAS² circuit breaker was not
reset. This was confirmed during the start-up check. The examiner requested a similar program
during this skill-test as he did the day before. However, when it came to demonstrating stalls, the
examiner asked for a slow flight up to first indication of stall, and not an actual stall. He asked for
call outs and a minimum loss of altitude recovery. The commander undertook the tasks of adding
power and retracting gear and flaps on the candidate’s request. It was IMC. During this exercise the
crew lost control of attitude and airspeed. The stall warning came on, but the airspeed decreased,
even with full power applied. Radar data show that the altitude increased 200 – 400 ft during the
period where control was lost. Airspeed decreased to about 30 kt and a sink rate of about 10 000
ft/min eventually developed. The airplane hit the sea in a near horizontal attitude about 37 sec. after
control was lost. All three on board were fatally injured.
The accident aircraft was used for coastguard duties and was modified with external sensors and
antennas. The AIBN made a Computational Fluid Dynamics analysis in order to determine whether
these installations influenced on stability and flight characteristics in the slow flight and pre-stall
regime. It was found that the modifications reduced the overall performance, but did not result in
any significant degradation of stability and control in this regime. There was no investigation as to
any influence on the characteristics of a fully developed stall.
The AIBN is of the opinion that this accident highlights the need for a change in the current training
on initial stall recovery techniques, especially the focus on minimum loss of altitude at the expense
of breaking the stall by lowering the nose and thus reducing the angle of attack.
The AIBN has issued two safety recommendations to the Norwegian CAA; one regarding the
conduct of skill-tests for pilots in a multi crew concept on single pilot airplanes, and one suggesting
The scary thing is I know of Checkies in Oz who do similar displays of bad airmanship! It is almost like they are 'fatalistic' or they have no concept of basic aerodynamics....anyway good catch and I agree a MUST READ!
The Metroliner has HORRIBLE stall behaviour. That's why a stick shaker AND a stick pusher are fitted, features normally found only on much heavier higher performance aircraft.
If the manufacturer and certification authority feel that these protections are necessary for safe operation then why on earth would you switch them off ????
If the manufacturer and certification authority feel that these protections are necessary for safe operation then why on earth would you switch them off ????
The in "IMC" just makes the whole exercise all the more chilling! Also the previous day's candidate....
....imagine how unnerving that would be! Sheesshh
....you'd step off the aircraft thinking...."I just dodged the biggest bullet!"
"having to use all her available physical strength to regain normal flight with the engines on full power and in IMC conditions."
....you'd step off the aircraft thinking...."I just dodged the biggest bullet!"
If the manufacturer and certification authority feel that these protections are necessary for safe operation then why on earth would you switch them off ????
Maybe some FOIs believe they can issue themselves a Reg.308 exemption from the Rules of Aerodynamics and the Law of Gravity.
In fact, if I am guessing identities correctly, Kharon was a Training Captain who refused to accede to the demands of one or more CASA FOIs, who were demanding deactivating the SA 227 SAS system, by pulling the Cb, and pulling the aircraft into a full stall.
And said Kharon obtained a letter from the TC holder absolutely prohibiting what (some) CASA FOIs were demanding.
Maybe this is OpsseverlyabNormal's "disgraceful behavior", not meekly going along with (some) FOI's demands.
A smart and highly experienced pilot refusing to accept the FOI's interpretation of CAO 40.whatever on stalls during training --- and to hell with the AIM ---- and everybody lived, in contrast to the Norwegian crash ---- which can hardly be called an accident.
Shades of D.P.Davies [UK ARB Chief Test Pilots, author of (Mis)Handling the Big Jets] and the Trident losses and fatalities, demanding a Tiger Moth stall in a modern piece of aerodynamics.
There are no new aircraft "accidents", we just keep repeating the same old same old.
Just like FOI's demands to "fail" ( by mixture or turning the fuel off ---- none of this wuzzie zero thrust) in aircraft not certified to survive an engine failure on T/O ----- because their chosen "black letter law" interpretation of the CAOs.
I guess we will just keep killing candidates from time to time.
Tootle pip!!
OpsNormal,
Thankyou for your post, all of a sudden things are now much clearer.
Leadsled, it is good to see you back once again demonstrating what you do not know and continuing to pontificate on all things aviation. You regularly make derogatory comments on what FOI's supposedly demand but are either unwilling or incapable of providing proof. Either put up or shut up please!
Although I personally know nothing of Kharon's background, I have yet to see CASA take action where it wasn't generally warranted and gut feeling tells me that if Kharon has been the subject of any regulatory discipline by CASA, it was more than likely justified.
Cheers!!
VH-MLE
Thankyou for your post, all of a sudden things are now much clearer.
Leadsled, it is good to see you back once again demonstrating what you do not know and continuing to pontificate on all things aviation. You regularly make derogatory comments on what FOI's supposedly demand but are either unwilling or incapable of providing proof. Either put up or shut up please!
Although I personally know nothing of Kharon's background, I have yet to see CASA take action where it wasn't generally warranted and gut feeling tells me that if Kharon has been the subject of any regulatory discipline by CASA, it was more than likely justified.
Cheers!!
VH-MLE
VH-MLE,
Perhaps you could tell us poor ignorant sods why disabling the SAS system and pulling a Metro into a stall, contrary to the AFM, is such a good idea.
While you are at it, how about telling us all what is technically incorrect about my last post.
And, no, I don't intend to satisfy your demands for "proof", as that would reveal identities of people who would probably prefer to keep a low profile.
All I will say is that, if I had to prove my statement in a court of law, the proof would be available.
Tootle pip!!
Perhaps you could tell us poor ignorant sods why disabling the SAS system and pulling a Metro into a stall, contrary to the AFM, is such a good idea.
While you are at it, how about telling us all what is technically incorrect about my last post.
And, no, I don't intend to satisfy your demands for "proof", as that would reveal identities of people who would probably prefer to keep a low profile.
All I will say is that, if I had to prove my statement in a court of law, the proof would be available.
Tootle pip!!
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Mr. MLE,
another typical fort Fumble response.
If Mr Ops Normal is who I suspect he is, then shall we say, people in glass houses shouldnt throw stones.
What proof do I need as to the veracity of Leadies statement? None except my own experiences with our "Safety" authority.
Mr. Kharons post was an invitation to read a report on an accident to enlighten us, and perhaps prevent a similar accident here.
Why that should invite personal vilification fails me.
Perhaps you might learn something if you actually read the link to his post.
Then again as a likely CASA representative you already know all there is to know about aviation.
"I have yet to see CASA take action where it wasn't generally warranted"
Hmm, there's another thread on here where an awful lot of people would disagree with you.
another typical fort Fumble response.
If Mr Ops Normal is who I suspect he is, then shall we say, people in glass houses shouldnt throw stones.
What proof do I need as to the veracity of Leadies statement? None except my own experiences with our "Safety" authority.
Mr. Kharons post was an invitation to read a report on an accident to enlighten us, and perhaps prevent a similar accident here.
Why that should invite personal vilification fails me.
Perhaps you might learn something if you actually read the link to his post.
Then again as a likely CASA representative you already know all there is to know about aviation.
"I have yet to see CASA take action where it wasn't generally warranted"
Hmm, there's another thread on here where an awful lot of people would disagree with you.
Last edited by thorn bird; 11th Dec 2011 at 19:13.
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The only exception I take here is the abuse of Virgil (Aeneid) and Dante (Divine Comedy) in the Phelan thread and the same puling, miserable little post here. In the vain hope of educating the unwashed, I offer the following for contemplation. I have avoided using the original text, that may be a bit too much on a Monday morning.
And my favourite line from the that epic:-
Dante.
Gate of Hell, canto 3. Cowards.
This idea of a marginal place--inside the gate of hell but before the river Acheron--for souls neither good enough for heaven nor evil enough for hell proper is a product of Dante's imagination, pure and simple. Possible theological justification for Dante's invention may be found in Apocalypse (Revelation) 3:16: "But because thou art lukewarm and neither cold nor hot, I will begin to vomit thee out of my mouth." Included among these cowardly souls--also known as fence-sitters, wafflers, opportunists, and neutrals--are the angels who refused to choose between God and Lucifer.
Courtesy University of Texas.
Gate of Hell, canto 3. Cowards.
This idea of a marginal place--inside the gate of hell but before the river Acheron--for souls neither good enough for heaven nor evil enough for hell proper is a product of Dante's imagination, pure and simple. Possible theological justification for Dante's invention may be found in Apocalypse (Revelation) 3:16: "But because thou art lukewarm and neither cold nor hot, I will begin to vomit thee out of my mouth." Included among these cowardly souls--also known as fence-sitters, wafflers, opportunists, and neutrals--are the angels who refused to choose between God and Lucifer.
Courtesy University of Texas.
Kharon: A slave? I take no slave, unless he has fought for his bodyrights [freedom from slavery] at sea.
Last edited by Kharon; 12th Dec 2011 at 05:43.
Well said there 'Led'
I fail to see the need to demonstrate a fully developed stall in an actual A/C of this caliber in the first place. I believe after a few years of flying machines around the sky that all is needed upon an endo is to be shown the signs & or be able to recognize the onset of a stall not the actual stall itself 'cause if you ever did get into a fully developed stall at low level especially in IMC in say a Metro for Eg then you had no place being there (flying). Simply understand how & why an A/C can stall (basic airmanship),know the signs & get on with it staying away from those situations in the first place.
Manufacturers go out of their way to protect us mere pilots with all sorts of devices to prevent stalling or at least give us a kick in the pants when it's about to happen with lights sirens shackers etc so why fool with that? It's beyond me!
Plenty of people have been killed foolishly playing with 'fire' (stalling A/C) so its stands to reason that sure show them the fuel for that fire,show them the match to start that fire with but sheeez never bring the two together when its known to be dangerous!
Wmk2
I fail to see the need to demonstrate a fully developed stall in an actual A/C of this caliber in the first place. I believe after a few years of flying machines around the sky that all is needed upon an endo is to be shown the signs & or be able to recognize the onset of a stall not the actual stall itself 'cause if you ever did get into a fully developed stall at low level especially in IMC in say a Metro for Eg then you had no place being there (flying). Simply understand how & why an A/C can stall (basic airmanship),know the signs & get on with it staying away from those situations in the first place.
Manufacturers go out of their way to protect us mere pilots with all sorts of devices to prevent stalling or at least give us a kick in the pants when it's about to happen with lights sirens shackers etc so why fool with that? It's beyond me!
Plenty of people have been killed foolishly playing with 'fire' (stalling A/C) so its stands to reason that sure show them the fuel for that fire,show them the match to start that fire with but sheeez never bring the two together when its known to be dangerous!
Wmk2
Last edited by Wally Mk2; 11th Dec 2011 at 20:22. Reason: grama & speeling:-)
Wally Mk 2,
With respect,( and I agree with what you say) in the specific case of the Metro, it is not so much a matter of the philosophy of what should be taught/demonstrated during an endorsement, but the vital need (if you want to keep living) to read and understand limitations and prohibitions in AFMs.
The DH Trident was the most famous of the "T-Tail" accidents, FAA was smart enough to not even require "fully developed stalls" in the B727 and quite a few Boeing models since.
For those of you interested in the details, the B727 Vs speeds are NOT based on "conventional" stall speeds, but are increments based on "minimum demonstrated controllable airspeeds".
The Metro has the ability to get into an unrecoverable deep stall, hence a tail chute used in certification test flying. I have not read the SA227 certification test schedule, so I do not know the basis of the V speeds for the SA 227, but I would not be surprised if they, too, were based on "minimum demonstrated controllable airspeed".
For a pilot or FOI, it is not necessary to know how the AFM numbers were obtained, only that they must be followed, and the AFM limitations and prohibitions rigidly observed.
My criticism of the FOIs involved in the matter to which I specifically referred ( and all documented in exchanges of emails and letters between the operator, its the head of C&T and the Type Certificate holder, M7 Aerospace, the successor to Fairchild Dornier/ Swearingen) was the demand that the "the law" ( CAOs) "required full stalls", and, therefor the SAS including stick pusher had to be disabled, and that "the law" took precedence over the AFM.
Tootle pip!!
With respect,( and I agree with what you say) in the specific case of the Metro, it is not so much a matter of the philosophy of what should be taught/demonstrated during an endorsement, but the vital need (if you want to keep living) to read and understand limitations and prohibitions in AFMs.
The DH Trident was the most famous of the "T-Tail" accidents, FAA was smart enough to not even require "fully developed stalls" in the B727 and quite a few Boeing models since.
For those of you interested in the details, the B727 Vs speeds are NOT based on "conventional" stall speeds, but are increments based on "minimum demonstrated controllable airspeeds".
The Metro has the ability to get into an unrecoverable deep stall, hence a tail chute used in certification test flying. I have not read the SA227 certification test schedule, so I do not know the basis of the V speeds for the SA 227, but I would not be surprised if they, too, were based on "minimum demonstrated controllable airspeed".
For a pilot or FOI, it is not necessary to know how the AFM numbers were obtained, only that they must be followed, and the AFM limitations and prohibitions rigidly observed.
My criticism of the FOIs involved in the matter to which I specifically referred ( and all documented in exchanges of emails and letters between the operator, its the head of C&T and the Type Certificate holder, M7 Aerospace, the successor to Fairchild Dornier/ Swearingen) was the demand that the "the law" ( CAOs) "required full stalls", and, therefor the SAS including stick pusher had to be disabled, and that "the law" took precedence over the AFM.
Tootle pip!!
Last edited by LeadSled; 12th Dec 2011 at 04:27.
Originally Posted by Wally
'cause if you ever did get into a fully developed stall at low level especially in IMC in say a Metro for Eg then you had no place being there (flying). Simply understand how & why an A/C can stall (basic airmanship),know the signs & get on with it staying away from those situations in the first place.
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Tid's, many thanks for the voice of reason.
I was having some trouble reconcilling why? when a person puts up a
a simple post, drawing attention to a safety related issue that begs
a reasoned debate descends into a vitriolic attempt at character
assassination of the poster based on a guess as to who the poster might or might not be.
I found that unconscionable so my apologies if I stirred the pot, I was more interested in hearing reasoned debate about the issue, rather than the bitter attack on the man....oops sorry! or woman (Gotta be politically correct here!!)
I was having some trouble reconcilling why? when a person puts up a
a simple post, drawing attention to a safety related issue that begs
a reasoned debate descends into a vitriolic attempt at character
assassination of the poster based on a guess as to who the poster might or might not be.
I found that unconscionable so my apologies if I stirred the pot, I was more interested in hearing reasoned debate about the issue, rather than the bitter attack on the man....oops sorry! or woman (Gotta be politically correct here!!)
Last edited by thorn bird; 13th Dec 2011 at 08:47.
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Although I personally know nothing of Kharon's background, I have yet to see CASA take action where it wasn't generally warranted and gut feeling tells me that if Kharon has been the subject of any regulatory discipline by CASA, it was more than likely justified.
Moderator
who were demanding deactivating the SA 227 SAS system, by pulling the Cb, and pulling the aircraft into a full stall
I have no specific background on the Merlin/Metro family so I can only make some general observations.
(a) generally SAS is there to fool the pilot into "seeing" a conventionally stable system when the aircraft wants to be longitudinally unstable
(b) with the SAS U/S or isolated, there is a real risk of stick force reversals at low speed high thrust combinations .. and this gets worse the slower and higher the power set
(c) think about it .. you start to go slower and the stick has to be PUSHED rather than PULLED to maintain that lower speed .. ie back to front .. recipe for near instant disaster if you don't know what you are doing
(d) generally there will be an AFM limitation with U/S SAS along the lines of a maximum thrust/power limit to keep this problem within controllable bounds
(e) if anyone intentionally disabled the SAS and then intentionally played with stalls and, perhaps, high power assisted recoveries .. then that would amount to something a little silly
(f) a letter from the TC holder absolutely prohibiting what (some) CASA FOIs were demanding. That's quite expected and comforting to know.
Examiners are not Gods. On occasion the pilot under test needs to establish some ground rules. The only occasions I exercised this was on GA IR renewals - "touch a throttle/mixture below <nominated height/speed> and I'll close both throttles and land straight ahead" - never put to the test on that one.
I have no specific background on the Merlin/Metro family so I can only make some general observations.
(a) generally SAS is there to fool the pilot into "seeing" a conventionally stable system when the aircraft wants to be longitudinally unstable
(b) with the SAS U/S or isolated, there is a real risk of stick force reversals at low speed high thrust combinations .. and this gets worse the slower and higher the power set
(c) think about it .. you start to go slower and the stick has to be PUSHED rather than PULLED to maintain that lower speed .. ie back to front .. recipe for near instant disaster if you don't know what you are doing
(d) generally there will be an AFM limitation with U/S SAS along the lines of a maximum thrust/power limit to keep this problem within controllable bounds
(e) if anyone intentionally disabled the SAS and then intentionally played with stalls and, perhaps, high power assisted recoveries .. then that would amount to something a little silly
(f) a letter from the TC holder absolutely prohibiting what (some) CASA FOIs were demanding. That's quite expected and comforting to know.
Examiners are not Gods. On occasion the pilot under test needs to establish some ground rules. The only occasions I exercised this was on GA IR renewals - "touch a throttle/mixture below <nominated height/speed> and I'll close both throttles and land straight ahead" - never put to the test on that one.
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Buggah
Oh well, probably for the best, but, I have just caught up with this, the response was elegant, but it will keep.
Thanks Tid.
Apologies to LS/TB/Sarcs 
(What I do???,is it on ?).
Thanks Tid.
Apologies to LS/TB/Sarcs (What I do???,is it on ?).
